Expansion joint



Dec. 19, 1944, .1. N. HELTZEL 2,365,550

' EXPANSION JOINT Filed Jan. 24. 1934 4 sheets-sheet l .8 Mn 1 v I.-

Dec. 19, 1944. J HELTZEL 2,365,550

EXPANSION JOINT Filed Jan. 24, 1934 4 Shets-Sheet 2 4 Sheets-Sheet sDec. 19, 1944. J. N. HELTZEL EXPANSION JOINT Filed Jan. 24, 1934 Dec.19, 1944. .1. N. HELTZEL.

EXPANS ION JOINT Filed Jan. 24, 1934 4 Sheets-Sheet 4 attorney PatentedDec. 19, 1944 UNITED STATES PATENT OFFICE EXPANSION JOINT John N.Heltzel, Warren, Ohio Application January 24, 1934, Serial No. 708,155

32 Claims.

This invention is a continuation, in part, of my application SerialNumber 507,492, filed January 8, 1931, now Patent No. 1,988,900, January22, 1935, and relates to improvements in removable expansion joint formsand dowel rod installation.

A primary object of this invention is to provide a removable expansionjoint plate or form for molding a space between abutting slabs ofconcrete together with means for forming a combination cushion andsealed joint in concrete roads, floors, roofs, walls and similar plasticstructures.

Another object of this invention is to provide means in connection withremovable expansion joints wherein the spalling or breaking away of theconcrete around the dowel structure on the face of the concrete isprevented.

A further object of this invention is to provide and method of removalof expansion joint forms and adjacent parts constructed in accordancewith my invention.

Figure 2 is a sectional view of a roadway showing my invention inrelation thereto and just before the removal of the expansion jointform.

Figure 3 is a similar view taken after the removal of the form andsealing of the joint.

Figure 4 is a detail perspective view of a portion of a flexible sealingmember.

Figure 5 is a detail perspective view of a portion of the bottom sealingmember, one of the side sealing members being associated therewith.

Figure 5a is a sectional view of a pair of typical concrete slabsprovided with dowel rods and illustrating the spalling or breaking awayof the concrete around the dowel rods on the face of the slabs and whichis eliminated by my invention.

Figure 6 is a perspective view of a slab of concrete positioned on aroad bed and equipped with my invention, a modified form of dowel rodbeing illustrated.

Figure 7 is a sectional view of a pair of slabs provided with the dowelbar illustrated in Figure 6. r

Figure 8 is a perspective view of one of the dowel bar guides.

Figure 9 is a detail perspective view showing a modified form of dowelrod guide.

Figure 10 is a perspective view of a pair of bar guides equipped withdowel bars and illustrating their relation to the removable joint form.

Figure 11 is a sectional view of the bar and guide illustrated in Figure10, the same being shown in position in the concrete slabs.

Figure 12 is a detail perspective view in section of a pair of concreteslabs provided with a modified form of sealing member.

Figure 13 is a detail perspective view of the sealing member illustratedin Figure 12.

Figure 14 is a perspective view similar to Figure 12 but illustratinganother modification of a sealing member.

Figure 15 is a detail perspective view of a portion of the sealingmember shown in Figure 14.

Figure 16 is a perspective view showing a pair of the shear plates.

Fig-ure 17 is a side elevation of the plates shown in Figure 16illustrating the position of the samefied form of one of the shearplates shown in Figure 17.

Figure 19 is a sectional view of another modiflcation of a shear platetogether with a form of dowel device.

Figure 20 is a sectional view of a tongue and groove construction formedin the slabs together with cooperating shear plates and dowel device.

Figure 21 is a sectional view of a modified form of dowel device.

Figures 22 and 23 are cross sectional views taken on the lines 22-22 and23-23 of Figure 21 respectively.

Figure 24 is a perspective view showing the arrangement of dowel barsand shear plates when used in connection with wall structures.

Referring more particularly to Figures 1 and 2, 1 indicates a concreteroadway under construction in which is illustrated a section thereofcomprising a pair of concrete slabs 8 and 9, bea tween which is appliedmy improved form Ill.

The form is made up generally of steel reinforcing plates II and 12which are placed upon opposite sides of a pliable mat or filler l3,preferably of rubber. The reinforcing plates II and I2 are cut away ornotched, as indicated at H, exposing the rubber filler l3 and foradmitting the dowel rods or bars l5. At the exposed portions of therubber filler l3, the same is provided with slots I6 which terminate inupper openings for receiving the dowel rods l5, all of which is clearlyillustrated and described in my pendin application, Serial Number507,492, of which this is a continuation-in-part.

The upper openings in the rubber filler l3 are made somewhat smallerthan, the diameter of the dowel rods IE to insure that the rubber fillerwill hug the dowel rods snugly. The dowel rods l (Figures 2 and 3) aresecured within the concrete slabs 8 and 9, serving to reinforce and keepthe slabs in alignment. Due to changing atmospheric conditions, theslabs expand and contract as the case may be. Should the ends of thedowel rods be firmly secured within the slabs, a buckling of the slabswould result when expansion took place with a consequent bending of therods and a spalling or breaking away of the concrete around the dowelrods, 'on the face of the spaced slabs, would result, as shown in Figure5a.

To overcome and eliminate this very undesirable condition, I provide thedowel rods with telescopic casings ll having enclosed flared endportions i8, fully illustrated in Figure 2. It will be apparent that theconcrete forming slab 8 only surrounds and rigidly holds the section i'lwhile the slab 9 secures within it the dowel rod l5, thus, any relativemovement of the slabs permit the rods E5 to slide back or forward withinthe casin ll without causing the rods to bend and spall or break awaythe concrete surround- 1 ing them. To facilitate the movement of therods relative to the casing, a suitable lubricant 20 is placed withinthe flared portion I8 and is forced out around the enclosed portion ofthe rods when movement between the rods and casings takes place.Before'the pouring of the concrete, the rods may be coated with a lowmelting point asphalt and are placed in proper position, aligned andheld therein by supports as indicated at 2i. These supports are adaptedto be driven into the roadbed or held thereon in any suitable manner.

Between the concrete slabs 8 and 9, I provide an air space M which isformed by the upper. lower and side sealing members 22, 23 and 24,respectively. To comprehend the action and function of these members, itwill be noted that the air space 2! is desirable in order to compensatefor the expansion of the slabs relative to each other and at the sametime provide an air cushion between the slabs. Under ordinaryconditions. dirt and other foreign matter would accumulate within thisspace and serve to retard or prevent the expansion of the slabs inproper alignment, resulting in a buckling of the slabs as shown in Fiure 5a. To prevent and overcome this condition, the lower sealing member23 is removably attached to the lower ortion of the form l0 before theform is placed in pos tion. The form is then placed in position asindicated in Figure 1. The dowel rods are then assed through the dowelrod o enin s in the form, and the supports 2| attached thereto toposition the same properly. The end or side sealing members 24 are nowsecured within the lower member 23 as indicated in Figure 5, and embracethe form iii.

The forms and other structure having been properly placed, the concreteis then poured in between a number of the forms and allowed to set asufficient length of time to permit the removal of the forms. After theremoval of the forms, it will be noted. the sealing members are retainedby the slabs. the member 23 be ng provided with flanges 25 and the sidemember 24 provided with tongue portions 26 for anchoring them to theslabs. These members may consist of very light non-corrosive metal orthe like and in the instance of the lower member 23. it is provided witha deformation 2! in its length constructed in a manner to ofier theleast resistance to the pressure of the slabs when they expand.

After the removal of the form til which exposes the space between theslabs for inspection and removal of any foreign matter, the uppersealing member 22, which is preferably constructed of spring material,is placed within the air space 2i near the upper surface of the slabs.The end portions 28, being so constructed that when inserted Within thespace, will embed themselves into the slabs of concrete, which is stillsumciently soft to seat them. After the concrete has hardened as shownin Figure 3, a suitable asphaltic or bituminous filler 29 is poured intothe space above the member 22 to seal the joint against water or otherforeign matter.

It will thus be understood from the foregoing, that by my invention, aroadway may be constructed, having joints in the form of enclosed airspaces for cushioning the adjacent slabs relative to each other tocompensate for the expansion and contraction of the material, preventbuckling of the slabs and the resultant movement of the dowel rodstherein without the usual breaking of the cement around them.

In the instances where it is desirable to construct wide roadways,particular reference being had to Figures 6, 7 and 8, I overcome thecurling action of the slabs and the bending of the dowel rods byproviding under beam members 3d and 3| in the slabs 36a and Bill), thesub-grade of the roadbed being excavated to form and receive them. Itwill be noted that the beam member 3| is provided with a longitudinalgroove Bib at the bottom.

An opposite groove 390 for dividing the slabs 30a and Ma along theirupper surfaces is also provided. These grooves function to induce acrack Kile to develop between grooves 3 lo and Elli). Suitable materialBld of an asphaltic or bituminous nature is used as a filler.

In order to prevent a lateral separation of slabs suitable tie rods 32are provided. Sheer plates 33 are imbedded into the oppositely disposedfaces of the slabs to prevent spalling or breaking away of the concretearound the dowel rods E5. The shear plates 33 project around and underthe bottom as at 3 2 of the slabs and are secured thereto by anchoringmeans indicated at 35. The plates 33 are of a fairly heavy grade ofmaterial so that the shear resistance thereof will substanstantiallyequal that of the dowel rods 85.

Dowel bars 36, substantially rectangular in cross section to preventbending, are provided and formed with openings 3l in one end for thereception of a lubricant 31", the upper and lower walls of the openingsbeing very thin. Sleeves 38 are positioned over the ends of the dowelbars so as to prevent the concrete from amalgamating thereto. The barsand sleeves operate in the same manner as described in the form shown inFigure 1. Shear plates 38, having anchoring portions 43 and 44 areembedded in the concrete and are provided with openings 39 formedtherein for the reception of the dowel bars 36. Auxiliary dowel rods 36together with sleeves (not shown, but which will be like sleeves I! ofFig. 1) are provided for the end shear plates. Plates (if! havingopenings for the reception of the sleeves are secured to the adjacentslab as illustrated in Figure '7.

When the slabs expand or move together, the thin walls of the opening 31in the dowel bars. will collapse in a manner to force the lubricantaround the dowel bars and thus permit free movement of the parts.

Figure 9 illustrates a modified form of shear plate formed of a fiatplate or sheet of material 40 provided with an opening Al for thereception of the dowel bar 42. A suitable anchoring pin 43 is securedthereto for retaining the plate Holes alone may be incorporated toreceive con-.

crete therethrough and aid in anchoring the members. The dowel bar 43and sleeve 49 operate within the slots in the upright portions 45 insubstantially the same manner as the rods and sleeves described inreference to the form shown in Figure 1. The lubricant 49 being placedin the end of the sleeve and forced around the bar by the actionthereof. Pins 44* passing through openings in the members and into theground hold them in proper position.

A modified form of upper sealing member is shown in Figures 12 and 18 inwhich the v-shaped longitudinal member 50 below the bituminous filler 29is provided with depending legs having slotted portions 52 adapted tofit over the dowel rods 53 and support the structure between the endfaces of the slabs 54 and 55, the legs being welded to the member 50. 4

Another form of upper sealing member is illustrated in Figures 14 and inwhich a substantially U-shaped section 56 of spring material is providedwith projecting prongs 51 for anchoring the section to the walls-of theslabs. One of the upper ends of the section 56 is bent at right anglesto form a flat surface 58 which is adapted to cover the space betweenthe end walls of the slabs iii and Eli as shown in Figure 15. The flatsurface 58 is also provided with projecting prongs ti so that theasphaltic or like material 62 will be firmly anchored thereto.

In overcoming the curling action of the slabs, I provided shear platesso constructed (Figures 16 and 17) as to offer the greatest amount ofbearing surface relative to the cement. These plates may be connectedtogether by a strip it of light collapsible material welded or otherwisesecured to the plates; The plates may be either circular, as indicatedat H, or square, as at 72. and arranged on the dowel rod 73 in a mannerto present the greatest bearing surface to the concrete in a verticalplane. This arrangement greatly assists in preventing the spell ng orbreaking away of the concrete. Both upper and lower edges of the platesare sharply defined to prevent the formation of round corners by theconcrete.

The bearing surfaces of the shear plates may be further increased, asshown in F gure 18, by bending the ends it at an angle. Thisconstruction tends to force the plates towards the slabs when underpressure.

In some instances, the plate 75 (see Fig. 19) may be drawn to form anopening in the pro- :lecting portion 75 and spot welded to the dowel rodH as at ii. The opposite plate 59 be ng secured on the sleeve 80 whichis formed by a tube or pipe section flattened at its outer end to closethe same.

The oppositely disposed faces of the slabs may be provided with a tongueand groove arrangement such as'is shown in Figure 20. The tongue 82being provided with a shear plate 83 coopcrating with the plate 84within the groove 85. The plate being anchored as at 86 in the concreteand provided with an opening for the reception of the dowel device 81. Amodified form of dowel device is depicted in Figures 21, 22 and 23 inwhich an I-beam 90 is imbedded in the slab 9|. A pair of bars 92 securedin the slab 93 are slidably positioned between the top and bottomflanges of the beam 90.

A strip of thin material 94, which may be wood, fibre or metal enclosesthe beams on both sides and at the end to prevent the entry of concreteduring the pouring operation. Suitable shear plates 95, embedded in theslabs, secured to the I-beam and bars make up the assembly. Thisconstruction presents a very rigid assembly to prevent vertical movementof the slabs relative to each other.

In wall structures, the dowel bars 98 with co operating shear plates 99(Figure 24) are ar ranged to offer the greatest resistance to lateralthrust.

It will be apparent from the foregoing that various changes andmodifications may be resorted to without departing from the spirit ofthe invention or scope of the appended claims.

Having thus described and set forth my invention, I claim:

1. In an expansion joint construction, concrete sections havingjuxtapositioned concrete .faces, a plurality of spaced relatively thickshear plates of minor area as compared to said faces and havingstress-receiving sides secured to said faces, and relatively slidabletelescoping means fixedly carried by the respective sections andsupported by said plates for maintaining said sections in alignment,said stress-receiving sides positioned in a manner to present theirstress-receiving area for receiving the thrust imparted by the sectionsduring a movement of said sections caused by atmospheric conditions.

2. In an expansion joint construction, concrete sections havingjuxtaposed faces in spaced relation, a tubular socket extending from theface of one section back into the interior thereof, said socket havinganchor means at its inner end and having a laterally enlarged fiatbearing portion over the face of said section, a dowel member extendingfrom the face of the opposite section and being slidably engaged in thesocket to transfer wheel loads from one section to another and permitfree longitudinal movement of the sections due to expansion andcontraction.

3. A dowel for expansion joints in concrete roads, consisting ofelements imbedded in the spaced walls of concrete road slabs, saidelements having anchor means extending into said slab for securing theelements in position, and a dowel member to slide freely into saidelements, permitting the free movement of said slabs to and from eachother due to expansion and contraction'of the concrete, said elements toabsorb the thrust of wheel loads and transferring said loads from oneslab to the other through said dowel.

4. A joint construction for spaced concrete sections, comprising aseries of substantially en larged bearing members imbedded in the faceof one of said sections, a series of substantially enlarged bearingmembers imbedded in the face of the opposite spaced section, saidbearing members having anchor means to secure the members in theconcrete dowel'bars passing through said members and hearing within themembers to transfer wheel loads from one slab to another and preventingvertical displacement of one section in relation to the other butpermitting longitudinal movement of the sections.

5. A joint for concrete slab construction comprising a reenforcingmember for extending between adjacent slabs, and reenforcing means forembedding in the slabs on each side of the joint and having a pair ofstress carrying arms for extending into the body of the associated slababove and below the member, the arms being adapted to transmit stressesbetween the member and slabs.

6.'A reenforced joint for concrete slab construction comprising areenforcing bar for extending between adjacent slabs, and reenforcingmeans operatively associated with the bar on each side of the joint,each means having stress-carrying devices adapted to extend into thebody of the associated slab above and below the bar for transmittingstresses between the bar and slabs.

'7. A- reenforced joint for concrete slab construction comprising areenforcing bar extending between adjacent slabs, and reenforcing meansoperatively associated with the bar on each side of the joint, eachmeans having a pair of stresscarrying arms adapted to extend into thebody of the associated slab above and below the bar for transmittingstresses between the bar and slabs and the arms of each pair beingangularly inclined to the bar.

8. An integral reenforcing member for concrete slab joint constructionhaving a reenforcing bar between adjoining slabs comprising a portionfor encircling the bar and contacting therewith and arms extending fromthe portion for embedding in the associated slab and adapted to transmitstresses between the bar and slab.

9. An integral reenforcing member for concrete slab joint constructionhaving a reenforcing bar between adjoining slabs comprising a flangedportion for encircling the bar and contacting therewith, and arms bentout of the plane of the flange for embedding in the associated slab andadapted to transmit stresses between the bar and slab.

10. A reenforcing member for concrete slab joint construction having areenforcing bar between adjoining slabs comprising a sleeve portionadapted to fit the bar on one side of the joint and having armsextending from the portion and adapted for anchorage embedment in theassociated slab, the arms being adapted to transmit stresses between thebar and slab.

11. A reenforcing member for concrete slab joint construction having areenforcing bar between adjoining slabs comprising a sleeve portion forfitting and having a length not less than the length of the bar on oneside of the joint, and arms extending from the portion for embedding inthe slab and adapted to transmit stresses between the bar and slab.

12. A bridging member for concrete slab joint construction having a loadcarrying bar between adjoining slabs comprising a sleeve portion forfitting and having a length not less than the length of the bar on oneside of the joint, and arms extending from the sleeve portion forembedding in the slab and adapted to transmit load between the bar andslab.

13. A reinforced self-supporting expansion joint structure for concreteroadways, comprising, in combination, an expansion .joint having loadtransferring dowels extending through the same and to opposite sidesthereof for embodiment in adjacent concrete slabs, reinforcing membershaving a supporting engagement with the dowels adjacent the sides of thejoint, each reinforcing member including reinforcing elements extendinginto the slabs above and below the dowel, the portions of said elementsextending below the dowel including base portions adapted to support andbrace the entire unit during the pouring of the concrete.

14. A joint for concrete slab construction comprising a reenforcingmember for extending between adjacent slabs, and devices for embeddingin the slabs on each side of the joint and having stress-carryingconnection with the member, the devices being adapted to transmitstresses between the bar and slabs.

15. A joint for concrete slab construction comprising a reenforcingmember for extending between adjacent slabs, and reenforcing means forembedding in the slabs on each side of the joint and having a pair ofstress carrying arms for extending into the body of the associated slababove and below the member and the arms of each pair being angularlyinclined to the member, the arms of each pair being adapted to transmitstresses between the member and slabs.

16. A joint for concrete slab construction com- I prising a reenforcingmember extending between adjacent slabs, and reenforcing means forembedding in the slabs on each side of the joint and having a pair ofstress carrying arms for extending into the body of the associated slabon opposite sides of the member and the arms of each pair flaringoutwardly with respect to each other and being angularly inclined to themember, the arms being adapted to transmit stresses between the memberand slabs.

17. A joint for concrete slab construction comprising an elongatedreenforcing member for extending between adjacent slabs for transmittingthe load therebetween, and a pair of arms on each side of the joint forextending into the slabs, the arms of each pair being located onopposite sides of the longitudinal axis of the member and having loadtransmitting connection with th member for transmitting the load betweenthe member and slabs.

18. A joint for concrete slab construction comprising a reenforcingmember for extending between adjacent slabs for transmitting the loadtherebetween, a flange portion encircling the member on each side of thejoint for embedding in the face of the slabs, respectively, and devicesadapted to be anchored in the slabs on each side of the joint, thedevices having load transmitting connection with the member and adaptedto transmit the load between the member and slabs and also beingconnected to the flange portions whereby the portions provide lateralsupport for the concrete in the funneling regions around the member.

19. A reenforced joint for concrete slab construction comprising areenforcing bar for extending between adjacent slabs, and reenforcingmeans operatively associated with the bar on each side of the joint,each means having a pair of stress-carrying arms adapted, to extend intothe body of the associated slab above and below the bar for transmittingstresses between the bar and slabs and the arms of each pair flaringoutwardly with respect to each other.

20. An integral reenforcing member for concrete slab joint constructionhaving a reenforclng bar between adjoining slabs comprising a flangedportion for encircling the bar and contacting therewith, the flangebeing adapted for embedding substantially in the joint face of theassociated slab, and armsextending from the flange and adapted foranchorage embedment in the associated slab, the flange being adapted toprovide lateral support for the concrete in the tunneling region aroundthe bar and the arms being adapted to transmit stresses between the barand the associated slab.

21. A reenforcing member for concrete slab joint construction having areenforcing bar between adjoining slabs comprising a sleeve portionadapted to fit the bar on one side of the joint, a flange portionencircling the sleeve and adapted to be embedded in a joint face of theassociated slab, and stress-carrying arms adapted to be embedded in theslab, the arms being adapted to transmit stresses between the bar andslab and also being connected to the flange portion to provide lateralsupport for the concrete in the tunneling region around the bar.

22. In highway construction wherein adjacent slab sections support themoving wheel load and where the-load of the initially loaded slab isprogressively applied to the next adjacent slab,-a structural memberspanning the joint between the slabs and having its ends entered intothe opposing faces of the slabs, rigid supporting members standing inaligned relation and embedded within the respective slabs and havingtheir opposed ends exposed through the faces of the slabs on oppositesides of the'joint, said supporting members having the ends of thestructural member entered thereinto and the assembly permitting slippageof the structural member during the advance and recession of the slabswhile maintaining the parts in alignment, anchoring means associatedwith each of the supporting members and embedded within the slab andserving in conjunction with the associated supporting members toreenforce the face of the slab and the region contiguous thereto, andserving to prevent lateral displacement of the structural member andchanneling of the slab in proximity thereto, the anchoring means and thesupporting means absorbing the wheel loads applied to the initiallyloaded slab and imparting the same to the structural member and acrossthe joint to the supporting and anchoring means in the next adjacentslab.

23. In a device of the kind described the combination of a dowel havingan element extending respectively into the areas of compression andtension of a slab and thereby providing means for absorbing anddistributing load applied to the slab and further transmitting said loadto the end of the element adjacent the face of the slab.

24. In a device of the kind described the combination of means forreceiving a dowel bar, and an element formed thereon extending from saidmeans and respectively adapted to extend into the regions of compressionand tension within a slab and thereby providing means for absorbing anddistributing load within the slab.

25. In a device of the kind described the combination of a dowel, anelement for receiving said dowel and a support for said combined doweland element, said element having means respectively extending into theregions of both compression and tension of a slab and providingadditional means for absorbing and distributing load ap--- plied to theslab at points adjacent to said element.

26. A reenforced joint for concrete slab con- 76 struction comprising areenforcing bar for extending between adjacent slabs, and reenforcingmeans operatively associated with the bar on each side of the joint andhaving a pair of stresscarrying arms adapted to extend into the body ofthe associated slab above and below and substantially in the samevertical plane as the bar for transmitting stresses between the bar andslabs.

27. A reenforced joint for concrete slab construction comprising areenforcing bar for ex.- tendlng between adjacent slabs, and reenforcingmeans operatively associated with the bar on each side of the joint andhaving a pair of stress-carrying arms adapted to extend into the body ofthe associated slab above and below the bar for transmitting stressesbetween the bar and slabs, the arms being shaped to provide anchorage inthe concrete for resisting endwise movement toward the adjacent slabface.

28. A reenforcing member for concrete slab joint construction having areenforcing bar between adjoining slabs comprising a sleeve portion forfitting and having a length not less than thelength of the bar on oneside of the joint, and a pair of arms extending from the portion insubstantially the same plane for embedding in the slab and adapter totransmit stresses between the bar and slab.

29. A reenforcing member for concrete slab joint construction having areenforcing bar between adjoining slabs comprising a sleeve portion forfitting and having a length not less than the length of the bar on oneside of the joint, and arms extending from the portion for embedding inthe slab and adapted to transmit stresses between the bar and slab, theends of the arms being shaped to provide anchorage therefor in theconcrete.

30. A reenforcing member for concrete slab joint construction having areenforcing bar between adjoining slabs comprising a sleeve portion forfitting and having a length not less than the length of the bar on oneside of the joint, and a pair of spaced arms extending from the portionfor embedding in the slab to transmit stresses between the bar and slab,the arms being symmetrically disposed on opposite sides of thelongitudinal axis of the portion.

31. Means for bridging a joint in concrete slab construction comprisinga load carrying bar for extending between adjacent slabs and reenforcingmeans operatively associated with the bar on each side of the joint andhaving a pair of load carrying arms adapted to extend into the body ofthe associated slab above and below and substantially in the samevertical plane as the bar for transmitting loads between the bar andslabs.

32. A reinforced joint for concrete road slabs comprising in combinationwith an expansion joint structure extending vertically throughout thedepth of the adjacent slabs and adapted to rest on the sub-grade, areinforcing dowel extending between-said adjacent slabs and through thesaid expansion joint structure, and reinforcing members having asupporting connection with the dowel on each side of the joint andincluding reinforcing elements extending from the sides of the jointinto the slabs above and below the dowel and away from the joint andalso including base portions adapted also to rest on the subgrade tosupport the entire unit during the pouring of the concrete or equivalentplastic.

JOHN N. HELTZEL.

